Added 1.2.x to intergration testing.

I also changed the 2.0.x version to the latest at the time 2.0.9.

 Fixed wiki_test.go to work with 1.2.x


The logic is the same as the previous version the only difference is instead of querying to see the table is there to delete it I just ignore the columnfamily doesn't exist error. 

Cassandra 1.2.x does not support the IF EXISTS  clause so I worked around it. If you look at the tests that reuse the table they only call CreateSchema once before they operate on the table and benchmark the performance of those operations.